Sterilizer and power-operated door therefor



May 28, 1968 A. B. HUsToN ET Al. 3,385,655

STERILIZER AND POWER-OPERATED DOOR THEREFOR INVENTORS.

51320 aDHusToN BY ROBERT LEGS May 28, `1968 A. B'. HusToN ET ALSTERILIZER AND POWER-OPERATED DOOR THEREFOR Filed Maron 5, 1964 3Sheets-Sheet 2 M. Sl

lNv ALFRED a. Hu i BY noeenr F. Les

ALVIN LODGE May 28, 1968 A. B. HUsToN ET AL. 3,385,655

STEHILIZER AND POWER-OPERATED DOOR THEREFOR Filed March 5, 1964 5Sheets-Sheet 5 FIG. 6 90-1.. sfo-+- 90 -i@ 9o 90- HVEN'IOR` ALFRED B.HUSTON ALVIN LODGE BY ROBERT ELES United States Patent O ice 3,385,655STERILIZER AND POWER-OPERATED DOOR THEREFOR Alfred B. Huston, Erie,Robert F. Les, Pittsburgh, and

Alvin Lodge, Erie, Pa., assiguors to American Sterilzer Company, Erie,Pa., a corporation of Pennsylvania Filed Mar. 5, 1964, Ser. No. 349,62514 Claims. (Cl. 21-91) ABSTRACT OF THE DISCLOSURE The present inventionprovides a motor controlled mechanism whereby a sterilizer door may beswung to closed position by a motor operating through a linkage. Theclamping action moves radiating arms outward under a rim on the chamberto clamping position and then swings the arms about a fulcrum with theouter end of the arm engaging the rim of the chamber.

This invention relates to sterilizers and more particularly, tosterilizers of the type used in hospitals and other environments wheresterile goods are required.

Sterilizers such as the one shown in Patent No. 2,592,- 705 had swingingdoors that were clamped in closed position on a chamber by a -manuallyactuated clamping mechanism. These clamping mechanisms had radiatingarms on the door. The outer ends of the arms engaged a fixed clampingmeans on the sterilizer and an intermediate part of the arms engage androck about a fulcrum on the door to move the ends of the arm axiallyrelative to the chamber and clamp and unclamp the door. A manuallyactuated lever was attached to a socket plate in the door which held theinner ends of the arms. The socket plate was rotated by means of thislever, to retract the outer ends of the arms from under the clampingring in the chamber. Thus, to close such a sterilizer door and clamp itthree manual operations were necessary. (l) Swing the door closed, (2)actuate the lever to move the ends of the arms outward under theclamping ring, and (3) rotate the hand wheel to clamp the arms. To openthe door the same three operations were necessary 1n reverse sequence.These manual operations -are time consuming and require the services ofpersonnel.

It is, accordingly, an object of this invention to provide an improvedsterilizer door and operating means therefor.

Another object is to provide a door and operating mechanism which issimple in construction, economical to manufacture, and simple `andeicient to use.

Another object of the invention is to provide an improved controlmechanism for a door.

With the above and other objects in view, the present invention consistsof the combination and arrangement of parts hereinafter more fullydescribed, illustrated in the accompanying drawings, it being understoodthat changes may be made in the form, size, proportions, and minordetails of construction without departing from the spirit or sacrificingany of the advantages of the invention.

In the drawings:

FIG. 1 is a front view partly in cross section of a sterilizer and dooraccording to the invention;

FIG. 2 is a top view of the door and actuating mechanism showing thedoor swung to open position in phantom lines;

FIG. 3 is a cross sectional view of the door actuating mechanism takenon line 3-3 of FIG. 4;

FIG. 4 is a longitudinal cross sectional view taken on line 4--4 of FIG.3;

FIG. 5 is an enlarged side view of the screw used in the operatingmechanism;

Patented May 28, 1968 FIG. 6 is an end view of the screw shown in FIG.5; and

FIG. 7 is a .planar development of the outer surface of the screw.

Now with more particular reference to the drawings, a sterilizer 21 hasa door 1 swingably supported thereon by means of a suitable hinge Hwhich is ixed to the door and pivots on the hinge pin P.

The door, shown has a clamping mechanism in some respects like thatshown in Patent No. 2,592,705, for example. However, instead of themechanism being manually operated as in the said patent, the doorlocking arrangement disclosed herein is operated by a mechanismincluding a motor 17 and the door is swung open and closed by means of amechanism including a motor 20, arms 31 and 32 and links 33.

The locking arrangement is made up principally of the post 2 iixed tothe door which extends outwardly perpendicular therefrom; the socketplate 9 which is slidaby supported on the post; the arms 29 which rockaround the fulcrum members 37 with their outer ends received by the rimon the chamber 1 and their inner ends received in the socket plate; andthe hollow, externally threaded screw 4 which has the nut 12 threadablyreceived thereon which, in turn, supports the housing 1).

The housing has the pin 19 on it which is received in the axial slot 91in the outside of the screw. The dowel 42 is ixed to the socket plateand received in the slot 90 of the screw and pin 7 which is xed to thesocket plate slides in a hole in the door during the initial part of theoutward movement of the socket plate 49 and screw 4 during the openingcycle. As soon as the pin 7 has moved out of the hole in the door, thesocket plate 9 is free to rotate. Thus, a continual drive of the motormoves pin 19 into the angular part of slot 91, thus rotating the screwrelative to the housing 10 and the dowel 42 moves in the slot 90, thusrotating the socket plate relative to the door and pulling the arms 29inward toward the center of the door and out of the openings 97 in thechamber.

The push rod 3 is fixed to the diaphragm 5 and is slidably received. Thepush rod 3 has the dowel 48 on the outer end thereof and this dowelengages the cap 16 when it is pushed outward, thus preventing the capfrom rotating when there is pressure on diaphragm 5 in the chamber. Thisis a safety device to prevent accidentally opening the door when thereis steam under pressure in the chamber.

The arm 31 is lixed to the door 1, arm 32 is xed to the shaft 35. Botharms are connected together by means of intermediate link 33 and act asa crank. Motor 20` acting through the gear .box 34 swings the arm 31around the pivot 35. The intermediate link 33 transmits this lforce fromarm 32 to arm 31. Thus the door is swung from the full line position 1to the dotted line position 1" by motor 20.

The door 1 is made up of the spaced plates 6 and 6' held in spacedrelation by the bracket 1' held in place by studs 79. The diaphragm 5has the push rod 3 fixed to it and pin 47 extends through the outer endof push rod 3. The gear box assembly is supported on the outer end ofpost 2.

Post 2 is fixed to plate 6' by studs 81 and extends outwardly at rightangles thereto. The gear lbox 10 is nonrotatably supported on the door.Handwheel 33, cap 13, cap 18, and nut 12, are rotatably supported on theouter end of the post 2; all of which are fixed together by stud 83 anddriven in rotation in either direction through gear 11 by motor 17.These elements are carried for rotation on the post 2 by anti-frictionbearing 45. Sealing rings 43 and 44 sealingly engage the outside of nut12.

The screw shown in detail in FIGS. 5, 6, and 7 is in the form of anexternally threaded cylinder which has a smooth cylindrical internalsurface which freely slides on the outside cylindrical grooved surfaceof post 2. Screw 4 has a reduced size end that is received in thecounterbore in socket plate 9. The screw has short slots 90 which aredisposed at 45 degrees to the axis of the screw and long slots 91 whichhave a straight part parallel to the axis of the screw and an angularpart disposed at 45 degrees to the axis. During the initial part of theopening procedure, screw 4 is restrained against free rotation on post 2by dowel 42 in the straight part of slot 90. Dowel 42 is pressed intosocket plate 9 which is received in cam grooves 90 in screw 4. Thus,straight grooves 91 guide screw 12 straight in and out on guide pin 19.Dowel 42 moving in slot 91 enters the angular part of slot 91 and causessocket plate 9 to rotate approximately 30 degrees during the last vpartof its outward movement to pull arms 29 radially inward and bring theirends from under flange 90 so that the door can be opened.,

Internally threaded nut 12 is driven by motor 17 by way of gear 11,energizes externally threaded screw 4 which is connected to socket plate9 -by dowel 42, creates in an out motion of socket plate 9 to lock andunlock the door.

Threaded screw 4 slides without rotating on post 2 during the first partof its outward movement because socket plate 9 and threaded screw 4 arerestrained against rotation by pin 7. Pin 7 is fixed to socket plate 9and slides in a hole in door 1. Pin 19 is fixed to housing 10 and isslidably received in slot 91. Slot 91 has a portion parallel to thecentral longitudinal axis of center post 2. Radially disposed pins 19solidly fixed in relation to the door 1 are attached to housing 10.Other radially disposed pins 42 are fixed to the socket plate.

Slidable engagement means consists of cam slots 91 in the outsidesurface of screw 4 so arranged that the slots 91 engaging pins 19 guidethreaded screw 4 with a linear outward motion during the initial part ofthe threaded screw travel. The slots 91 have a screw-wise lead duringthe outer part of the threaded screw travel as the pin 19 enters theangular part 93 of slot 91.

Cam slots 91 engaged by pins 19 have a screw-wise lead in the oppositedirection to angular parts 93.

During the inner part of the travel threaded screw 4 and socket plate 9move together because socket plate 9 is restrained against rotation bypin 7, pin 42 cannot move down inclined slot 90 because .pin 19 slidesin the axial part of slot 91 preventing threaded screw from turningduring the inner part of its travel.

During the outer part of threaded screw 4 travel socket plate 9 is freeto rotate since pin 7 has moved out of the hole in door 1. Socket plate9 has moved into engagement with shoulder 94 on housing 10 therefore itcannot move outward any further.

As threaded screw 4 continues its outward travel, pin 19 enters theangular part 93 of slot 91 rotating threaded screw 4 in a firstdirection. Since threaded screw 4 is moving outward and socket plate isstopped at this Stage by housing pin 42 is urged to move in slot 90.

During this part of the travel, the grooves 90 of threaded screw 4 arehaving engagement with pins 42 and cause rotation of socket platerelative to screw 4. Screw 4 is at the same time rotating relative tohousing 10. These two relative rotations are additive giving the socketplate double the angular travel of a single system.

Guide pins 7 which may be two in number, for example, are fixed to thesocket plate 9 at their outer ends and extend axially thereto. The pins7 freely slide in holes in plate 6. The pins 7 thus prevent the socketplate from rotating relative to the door during the few initialrotations of nut 12, which produces the first part of the movement ofthe socket plate 9.

The arms 29 extend radially from the socket plate 9. These arms haveballs 36 fixed to their inner ends that are received in sockets in thesocket plate and are held in place by the studs 79 and lock washers 80.The arms 29 extend through loops 37 which are fixed to the door and overthe fulcrum members 37 which are slightly raised above the outer surfaceof the door. The sterilizer has a flange fixed to it which defines aspace between it and the end of the sterilizer. The outer ends of thearms 29 are received under flange 90. When the socket plate 9 is movedoutward by the nut, the outer ends of the arms 29 will rock inward awayfrom this flange 90 and allow the door to release. When the nut 4 ismoved inward, the outer ends of the arms will be forced away from thesterilizer chamber. Thus, they will rock around the fulcrum members,their ends will exert a force on the flange 90 and force the door intosealing engagement with the end of the sterilizer.

The gear 11 is keyed to the nut 12 and the nut 12 is fixed to the cap 16by means of the cap screws 91. Gear 11 and nut 12 rotate freely onbearing 45 which supports the nut 12 on post 2.

The motor 17 is reversible and may be of the general type commonly usedon electric hand drills or it could be of any other suitable type ofmotor. The motor 17 is supported on the door 1 and it has the shaft 21with the worm wheel 66 keyed thereto. The worm wheel `66 engages theworm gear 11 and rotates it both backward or forward, depending on thedirection of rotation of the motor. The shaft 21 is connected to themotor drive shaft by means of the collar 28 which is rotatably receivedin the hub assembly 27 and supported on pins 23. Pins 23 rigidly supportthe motor 17 on gear box 10.

It will be seen that the motor 17 will rotate the worm gear 11 throughthe worm wheel 66 which will, in turn, move the screw 4 in or out alongthe post 2. When the motor 17 moves the inner ends of arms 2'9 away fromthe door, the outer ends will release their clamping force on the underside of flange 90.

As the socket plate moves further from the door, pin 7 moves out of thehole in plate 6. As the socket plate is drawn out still further pin 7 isno longer restraincd against lateral movement and the socket plate isnow free to rotate, pin 19 enters the inclined part of slot 91. Thisproduces a torque on screw 4 and socket plate 9 rotates as pin 19follows slot 91. Thus, the initial outward movement of the socket platewill not rotate but will cause the arms 29 to rock around their fulcrum37' and release their clamping force on the door. Further movement ofthe socket plate will cause it to rotate as it moves, as pin 7 moves outof its hole in the pin 19, enters the angular part of the groove 91 anddowel 42 moves in groove 90. This will move the outer ends of arms 29radially inwardly to disengage the door rim 90'. Motor 20 can then beenergized to swing the door open. Motors 17 and 20 can either or both becontrolled by manually actuated switches or by any other suitablecontrol circuit.

The foregoing specification sets forth the invention in its preferredpractical forms but the structure shown is capable of modificationwithin a range of equivalents without departing from the invention whichis to be understood is broadly novel as is commensurate with theappended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A sterilizer comprising a chamber adapted to contain gas underpressure,

said chamber having an opening, a door closing said opening and meansswingably attaching said door on said chamber,

means to open and close said door,

clamping means to clamp said door in closed position and motor means toactuate said clamping means, said clamping means comprising armssupported on said door, each arm having one end disposed adjacent thecenter of said door and extending outward and terminating adjacent tothe edge of said door,

said arms having means thereon to engage clamping means on said chamber,

means to move said arms to clamp said door in closed position,

said means to move said arms comprising a motor, a screw member on saiddoor, a nut on said screw,

motor means on said door to move said nut on said screw toward and awayfrom said door and means on said nut engaging said arms moving said armswith it to clamp said door to closed position and to release said door.

2. The sterilizer recited in claim 1 wherein,

said nut has a gear member connected thereto and said motor has a shafthaving a gear thereon engaging said gear on said nut.

3. The machine recited in claim 2 wherein,

means on said arms to clamp said door comprises a ulcrum member on saiddoor adjacent the outer end of each said arm, and said means on saidchamber comprising a member on said sterilizer receiving the outer endof each said arm thereunder whereby said arms urge said fulcrum memberand thereby urge said door to sealing relation when said nut is driventoward said door.

4. A sterilizer comprising a chamber and a door,

means to swing said door open and closed,

means to clamp said door in closed position,

said clamp means comprising a post iixed to said door generally at thecenter thereof,

threaded means on said post,

a motor on said door having drive means engaging said threaded memberfor rotating said threaded member,

a socket plate on said post,

said threaded member engaging said socket plate, moving said socketplate with it toward and away from said door,

arms 4having one end engaging said socket plate, the other end adaptedto engage said sterilizer chamber,

said arms forcing said door into sealing engagement -with said chambertank when said motor moves said threaded member in one direction.

5. The sterilizer recited in claim 4 wherein,

said motor is connected to said threaded member by means of a guidemember said threaded member being slidable on said guide member towardand away from said door.

6. The sterilizer recited in claim 4 wherein,

said motor is supported on said post with the sha-ft of said motorgenerally perpendicular to said post.

7. A sterilizer comprising a chamber and a door,

means to swing said door open and closed,

means to clamp said door in closed position,

said clamp means comprising, a post xed to said door .generally at thecenter thereof,

a hollow screw slidably supported on said post,

a' socket plate supported on said screw for movement toward and awayIfrom said door,

means on said socket plate engaging said door holding said socket plateagainst rotation with said nut, during a part of its outward movement,but allowing said socket plate to move toward and away from said door,

a nut on said screw,

a motor supported on said door,

said motor having drive means connected to said nut whereby said nut maybe selectively driven on said screw to move said screw toward and awayfrom said door, p

arms havin-g their inner ends attached to said socket plate and theirouter ends adapted to engage means on said chamber adjacent theperiphery of said door,

fulcrum means on said door engaging an intermediate part of each saidarm',

said arms being rocked on said fulcrum by said motor whereby said dooris forced into sealing engagement with said chamber.

8. The sterilizer recited in claim 7 wherein,

said post is hollow and has a push rod extending therethrough,

a diaphragm on said door, the inner end of said push rod engaging saiddiaphragm and locking said screw against rotation when said chamber hasa medium under pressure therein.

9. In combination, a sterilizer having a chamber with a door and a meansto close and -fasten said door,

said means to fasten said door comprising a socket member adjacent saiddoor movable toward and away from it,

arms each having means on one end engaging said socket plate and theother end engaging said chamber,

a reversible motor on said door, screw and nut means connecting saidsocket member to said motor,

said arms forcing said door into sealing engagement with said chamberwhen said motor drives said nut to swing said arms in one direction,

said arms releasing said door when said motor drives said nut to swingsaid arms in another direction.

10. The door recited in claim 9 wherein,

said screw and nut means comprises means to rotate said socket memberrelative to said door when said nut has rotated beyond a predeterminedamount during opening whereby said arms are moved radially inwardly torelease them from said chamber.

11. In combination, a chamber, a door and means to clamp said door inclosed position on said chamber,

said door -having arms having inner and outer ends,

the inner ends of said arms terminating adjacent the center of saiddoor,

means on said chamber engaging said outer ends of said arms when saiddoor is closed and clamped,

means on said door engaging the inner ends of said arms,

moving the outer ends of said arms to force said door to sealed positionon said chamber and movin-g said arms toward the center of said doorfrom engagement with said chamber and a single drive means actuatingsaid means on said door, said means on said door engaging said armscomprising a screw member, a motor on said door, and connected to saidmeans recited for operating said means,

means attaching the inner ends of said arms to said screw member,

means to guide said screw member toward and away from said door,

means on said screw member restraining it against rotation during itsinitial movement ifrom said door whereby the clamping force on said armsis released,

and means on said screw rotating it durin-g its final movement from saiddoor whereby said arms are moved from said means on said chamber.

12. The combination recited in claim 11 wherein,

said screw member has external threads thereon and a nut is disposed onsaid door,

said screw having a iirst and a second rotating means thereon,

said first rotating means holding said motor against rotation relativeto said screw member during the initial part of the outward movement ofsaid screw,

a rst member holding and engaging said door, holding said screw againstrotation relative to said door during the initial part of its rotation,

said rotating means rotating said screw member relative to said doorduring the nal stages of its rotation.

13. -In combination, a chamber and a door with sealing means for forminga seal between said door and said chamber,

and means to force said door into sealing relation with said chamber andsaid sealing means,

said means to force said door into sealing relation comprising spacedoutwardly radially extending arm members extending generally parallel tothe plan of said door,

fulcrum members disposed between said door and an intermediate part ofeach said arm,

means on said chamber to receive the outer ends of said arms thereunder,

a center post on said door extending outward generally perpendiculartherefrom,

socket plate slidably supported on said post,

inner end of each said arm being secured to said socket plate,

a hollow externally threaded screw slidably supported on said post,

a nut threadably engaging said screw,

a housing supported on said nut,

motor means on said housing for rotating said nut to move said screwtoward and away from said door,

a pin on said socket plate slidably engaging said door during theinitial part of its movement away from said door whereby said socketplate is held against rotation during said initial movement,

said pin disengaging said door during the nal part of said socket plateoutward movement,

a dowel member on said socket plate,

a first and a second slot in said screw,

said first slot receiving a member on said housing holding said housingagainst rotation relative to said screw during said initial part of saidscrews outward movement and rotating said screw relative to said housingduring the nal part of its movement,

said second slot rotating said socket plate relative to said screwduring the nal part of its outward movement whereby said router ends ofsaid arms are moved toward the center of said door and from said meansto receive the outer ends of said arms.

14, The combination recited in claim 13 wherein,

a push rod is disposed concentric to said post,

a diaphragm on the inside of said door and engaging said push rod,

and means on the outer end of said push rod engaging means on said nutfor holding said nut against rotation when a medium under pressure isdisposed in said chamber.

References Cited UNITED STATES PATENTS JAMES H. TAYMAN, JR., PrimaryExaminer.

